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Messages - Chaudhari Evans

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Last Friday night at the Atoka County dark site as fatigue started setting in @ 4am I put the ES100 20mm into the Starmaster's focuser for a tour around Cassiopeia. I had not visited that area this year nor had I much used that ep in the session. M103 was 1st up and I found myself counting stars (>80) as only 9 are visible from home most nights. M52 and NGC457 followed. Somewhere in the process of observing those objects at only 105x with a 3.9mm exit pupil and 57 arc' field it started to dawn on me that the view was really good. High contrast dark background and sharp bright stars. Really quite good.
Frankly, I have considered this ep the least capable ep in my main kit and have considered replacing it with a Lunt/APM HDC 20mm 100<sup>o</sup> after a comparison that I just pretty much assumed the Lunt/APM would win. But after looking up a dozen more open clusters in Cas and really enjoying the view of each, I'm just not so sure the project is worth the trouble. You can read others' lukewarm response to the ES100 20mm and I cannot argue with their experience. But as I used mine on that night I was quite satisfied with the views it put up. If this really is my least capable unit, I'm OK with that fact.
To be clear, I have never even seen a 21 Ethos. I expect it is likely the finest in the focal range for many scopes including mine. But I am just not motivated to spend that long $ on one.

Hi Dick,

I owned the ES 20 100°, 14mm 100°, 9mm 100° &amp; 5.5mm 100° eyepieces.
At the same time I owned the Lunt 20mm 100°, 9mm 100° and 5mm 110° eyepieces.
Also own all the Ethos eyepieces.

Head to head compared the ES vs TV vs Lunt in as close to equal focal lengths as possible in my 11" and 13.1" Dobs
11" with Zambutto mirror, 13.1" with Norman Fullum refigured mirror. Both mirrors with fresh new coatings.
Best of the bunch are the TV Ethos.
2nd place just by a whisker are the Lunts.
3rd place are all the ES versions

When I use these ultra wide eyepieces:
I have kept all the Ethos but rarely if ever use them - 21mm and 17mm are especially heavy compared to the Lunt 20mm.
Kept and nearly 100% of the time I use the Lunt eyepieces.
Sold all the ES versions except the 14mm because their is no equivalent Lunt 100° focal length - however, Lunt is releasing the new 12.5mm 100° version in the near future. If the new 12.5mm is anything like the other Lunt 100° eyepieces, the ES 14mm eyepiece is out the door.

The Lunt 20mm is better optically than the ES 20mm 100° - much lighter (easier balance) and focuses further outward than the ES 20mm. I have a dedicated Baader MPCC with correct spacing for the Lunt - the ES 20mm required so much in focus I could not get it to reach focus. (My direction comparisons of the Lunt 20mm vs the ES 20mm were in the 13.1"
where there were no focusing issues),

In my opinion, sell the ES 20mm and look for the 20mm Lunt (used if possible). You may even have extra $ in your pocket.

I'm tempted to replace my ES 20mm 100 with a Lunt 20mm. Especially, now that Don carries Lunt at EyepiecesEtc. The Lunt seems to get fantasic reviews.

All good may want to step back and breathe deep.....and assemble the eyepiece  outside of the barrel, mask it up with tape   and test it , then disassemble and  remount it ...knowing it is correct.

Attached Thumbnails

ATM, Optics and DIY Forum / Re: Playing around with PLOP
« on: February 09, 2018, 02:27:06 AM »
Similarly, you can take an optimized design and round dimensions up or down slightly to see how much (or little) the error is affected. You may find that by rounding off dimensions you can execute the design far better for symmetry with negligible increases in error.

I discovered on my six point cell for a 10" f/4.7 that rounding dimensions up 0.018" allowed me to use 3.000" dimensions on all the pivot spacings and RMS error increased only a couple of tenths of a nanometer.

Beginners Forum / Re: Tools in your travel toolkit
« on: February 02, 2018, 11:13:52 PM »
A tank of gas...

Never travel out to darker darkness with out it. IME. Fuel up on the way out to observe. Every time.

Another vote for the very well recommended knobs, rather than screws or bolts. Where ever it's possible to do so.

I like cargo pockets on me, for my ep's. Rather than my once upon a time racks or tripod trays. Ep's only ever in those specific pockets. Clean, sorted, covered, warmed.

Dark red nail polish. So any flashlight can become an observing flashlight, in a pinch, if needed.

Solar rechargeable flashlights in my rolling observatory. These things have been around for awhile, and are the best thing since sliced bread. Batteries not required... for years.

Caffeine and sugar free drinking fluids. Rehydrating increases visual acuity.

Light Pollution Topics / Re: court order
« on: January 31, 2018, 12:34:55 PM »
In a way I'm glad to see others have the same problems I do...but that being said there are some people that are impervious to any kind of being approach... Good or problem seems like a reasonable fella but the wife is so scared of living in the country I'm wondering why they do.....when I put my building and deck in he was there every day..even helping at one point...he was aware what it was etc....he has lived there for years outside lights were in place and I there for chose the placement of my new digs to make everything friendly for all involved....first week was OK...second week found a pole lamp half way across the lawn and right where it burned my eyes out...story goes his weed Wacker was stolen.....he left it next to the main road on the edge of the ditch and went inside for a 2 hour nap...guess he figgered it would still be there next day.....not sure what frappin good this light will do him but I've erected shades of studio lighting cloth....and once in a while. My laser or flashlight will flash cross a window.....and my new app of coyote and wounded rabbit calls sounds real nice on my speaker system.....I've no avail some people just won't think or compromise..... So I do my thing best I can....and he thinks that 150 watt bare bulb lamp post will protect his stuff...that's his thing....just say to get it out of my system somehow... Thanks for letting me do that.

Beginners Forum / Re: Thoughts on video astronomy
« on: January 31, 2018, 11:29:48 AM »
Yes, wear my swimsuit, sit down on a towel, get a Campari and open the is way cheaper

Professional astronomers do not stargaze (or are not supposed to stargaze), rather they take measure and collect data, and both tasks are far more effective if performed through purposely designed sensors. And IMHO it is a very good thing that the usefulness of the human eye as sensorhas failed long time ago.

I do not have any conceptual aversion for EAA, but can not forget that what I am watching is a picture on a screen, whose fundamental nature is exactly the same of any other astropicture, be it an APOD or a shot through the cellphone.
It is useless? Absolutely not.
It is the same as stargazing? I believenot.

The whole purpose of my posts is to underline to the OP that EAA and stargazing are soo distant that he may found one of them highly disappointing and the other completely satisfying (or both disappointing...) and that EAA is very close to conventional astrophotography.

My wife is not a stargazer (despite this fact is developing an awkward fascination for deep sky AP), and usually is not really moved when show her something into the eyepiece; but when showed her the HorseHead nebula and the Veil"real time", right on the screen from our home all she said was something like "well, it looks better in the picture we shot yesterday".

I don't believe that EAA and visual "are soo distant" at all but are complimentary to one another. I observed visually for decades and also did astrophotography with film. I considered both activities amateur astronomy and each as>validas the other. Same with EAA. Visual does not have more cache than EAA, it is just a different path to achieve the same end. I see a lot of fundamental misunderstanding and misinformation about what EAA is or does. Just more proof that a little information is dangerous. Visit the forum and become informed before making "informed" statements.

I would go 12" hands down....the 14" is way too hefty and bulky.

General Astronomy & Observing / Re: Window scope?
« on: January 31, 2018, 04:10:04 AM »
I should have clarified my situation. My views are not through the window glass. Our mild climate permits popping out the screen and observing though the unimpeded window opening.



<p class="citation">Wwilmoth69, on 24 Jun 2017 - 2:33 PM, said:<a href=";module=forums&amp;section=findpost&amp;pid=7956855" rel="citation">[/url]<blockquote class="ipsBlockquote built" data-author="Wwilmoth69" data-cid="7956855" data-time="1498307592">

In a different post I talked about sharp caps ability to polar align
It looks really simple to use and pretty darn accurate. Prob still need to drift maybe but haven't talked to anyone that's used it.
I don't want to spend 7k. 3k is my limit on a mount and the gm811 maxes that out with the hd tripod. It's a pier mount so I could permanatly mount it later on if I build a building but I doubt I'll do that but maybe if I can build a small cover that's good enough and light enough to move but with my temperature swings I don't feel comfortable doing that safer to just bring it in
So all that being said do u think a gm811 will track well enough if my alignment is good for a 2000 fl scope or is that just reaching to far for my price range
I don't think you'll need to drift if you do a careful alignment with Sharpcap. For 300-second and shorter exposures, you definitely won't. The single drawback to Sharpcap is that currently, unlike Polemaster, it doesn't take your latitude into account. Due to refraction, if are close to the equator than about 30-degrees, a couple of minutes from the pole will be as good as it gets. That it still more than good enough for almost any imaging you'll want to do, however. I will never drift, use a polar borescope, or fiddle with ASPA again.
The Losmandy will handle 2000mm of focal length certainly, in the form of a C8 anyway.

I'm in Tennessee at 36.06 lat. So I'm close lol
I could try sharp cap first then if not good then I can always add something else later
At 31-degrees (my location) Sharpcap is fine. I'm guiding, of course, and keep exposures down to 300-seconds or less, but my dec corrections are minimal, including with my C8.

Beginners Forum / Re: thinking of getting a refractor...
« on: January 31, 2018, 02:56:12 AM »
Nice scope! I have looked through the Orion version and I was impressed.

And...B&amp;H has the Skywatcher 100ED for sale at $699. Its an f/9 but its only around 10lbs.. I'm considering it as a good backyard grab and go. Nice deal and should not have any color issues at f/9...Dangit this refractor bug is dangerous

Beginners Forum / Re: Meade Polaris 130mm vs Orion StarMax 90mm
« on: January 31, 2018, 01:25:44 AM »
I have read here that the Meade does have a parabolic mirror. My concern is the rather thick plastic spider.
Yes, my 100mm f/4 has three thick plastic vanes. I was told that that helps to diminish the vane flares when viewing brighter objects; the so-called "Christmas stars". The thicker vanes presumably spread out the diffracted light; evenly more or less, but the damage to the image is still there. Also, with the Meade, you can't adjust the vanes when centering the secondary mirror under the focusser; obviously not an important feature at that price-point.

Eyepieces Questions & Recommendations / Re: Really good short barlows?
« on: January 30, 2018, 11:26:57 PM »
Thanks George,
At that price they are worth a try. Just ordered the Meade 2x Barlow.

I've tried all kind of arrangements and for a closed tube, air blowing up the tube has worked the best.


As you can see in the pictures, the collimation system on this particular telescope isn't the standard. I actually spoke with a guy at Explore Scientific today, and he explained to me there's been lots of issues with this thing. Enough so, that they said the solution would be to build and send me a new complete secondary to replace the one that came stock in the OTA.

Beginners Forum / Re: Scope Design Purchase?
« on: January 29, 2018, 10:47:09 PM »


As is often the case you are mixing things that are best not mixed.

Visual is all about aperture - 10 to 12" is nice aperture, but it is going to get heavy.

AP is all about the mount - 80 to 100 mm APO refractor on an EQ mount - not the best for visual.

You really want two telescopes or one mount and two OTA.

Likewise you have a weight concern. So let's try to keep components under 25 pounds.  It might take several trips to move the scope but no single part should be more than 25 pounds.
The VX 9.25 might be a better choice for visual and AP. $2200
OTA is 20 pounds.  Counter weights are 12 pounds each. Tripod is 18 pounds.  As a compromise scope between visual and AP this might be a very good choice. You can move it in pieces.  Autoguider port for long exposure imaging.
https://www.celestro...grain-telescopeAdd an 80 mm APO refractor for the more serious AP sessions - $999

I've gotta admit, Ed, you nailed this one right on the head. I, too, have had back surgery so I've got to watch myself. I bought the XX12i dob as my dark sky scope BECAUSE I could break it down but I'm strictly a visual guy now. Your choice will do both and will not tax his back. The VX 9.25 nails it! STARKID2U
Hey sorry I've not replied, been a tad busy last few weeks. Anyways, that VX looks interesting for what I was looking for. Though I did some research and noticed that the 11" ones OTA is only 27lb and the Tripod is the same weight as the 9.25". This might be a winner. And with the cost, i can see "convincing" the wife at a later date that I just need to have a Refractor for better imaging....

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